Tycho Brahe was a Danish astronomer. He lived from 1546 to 1601. He was the most prominent astronomer in the 16th century. Tycho�s parents were very rich and wanted him to become a lawyer. Alchemy and astrology were Tycho�s main interests.
On November 11, 1572, Tycho spotted a new star in the constellation of Cassiopeia. Tycho proved that this star was actually a new star, not a comet. This star is usually known as Tycho�s supernova. Finding this star turned his interest back to astronomy. With financial help with the king of Denmark, Tycho built an observatory and he named it Uraniborg. Tycho also built an alchemical observatory in the basement of Uraniborg. After twenty-five years of observing the sky at Uraniborg, it was shut down after Tycho argued with the new king of Denmark. Tycho searched for a new place for him and his equipment at various courts. In 1599, Tycho became the holy roman emperors� mathematician. As an assistant, Johannes Kepler joined Tycho and helped him with his calculations. Tycho wanted his calculations to prove his theories right. His theory explained that the Earth was the centre of the universe and that the sun went around earth, but all the other planets circled the sun while the sun orbited earth! Tycho�s observations of planetary motions were observed with open sites, (telescopes were not invented until about 1609.) His observations were much more accurate than observations of other astronomers before him.
After Tycho�s death, Kepler took over the position of the emperor�s mathematician. Tycho�s observations of planetary motions helped Kepler (who believed in the Copernican theory of which the sun was the center of the universe and that all the planets revolved around it) deduce his three laws of planetary motions and to make the astronomical tables, the Rudolphine Tables in 1627. These tables influenced other astronomers into thinking that the Copernican theory was right. But up until the middle of the 17th century, people still believed in Tycho�s theory because with his theory, you did not have to think about all of earth�s motions, because Tycho believed that it just sat there in the middle of the universe!
